The reinforcement of four interresponse times in a two-alternative situation.
Pigeons can match payoff odds for tiny timing classes on each key while overall key rates still interact.
01Research in Context
What this study did
Shimp (1971) worked with pigeons in a lab box with two keys.
Each key paid off on its own VI schedule, but with a twist.
The birds only got grain when their time between pecks matched one of four short classes on that key.
What they found
The birds matched the payoff odds for each IRT class on each key.
Yet the total peck rate on one key still rose or fell with the rate on the other key.
In short, fine timing stayed independent while overall output stayed linked.
How this fits with other research
PLISKOFF (1963) first showed that pigeons split their pecks between keys to match payoff odds.
Shimp (1971) proves this rule also holds inside tiny timing classes, not just total responses.
Shimp (1968) used one key and saw two IRT clumps shift with payoff size.
The two-key setup in Shimp (1971) shows the same clumps can be shaped separately on each key, extending the one-key result to concurrent schedules.
Why it matters
When you shape rapid bursts or long pauses, remember the bird can learn separate timing rules for each key, yet overall key preference still talks to the other schedule.
If you run concurrent teaching programs, watch both the micro-timing you reinforce and the macro-choice between tasks; they obey different rules.
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02At a glance
03Original abstract
Pigeons pecked for food in a two-key procedure. A concurrent variable-interval variable-interval schedule of reinforcement for two classes of interresponse times was arranged on each key. A visual stimulus set the occasion for potential reinforcement of the four operant classes: shorter and longer interresponse times on left and right keys. In Exp. I, the relative frequency of respones on a key equalled the relative frequency of reinforcement on that key. In Exp. II, the relative frequency of an interresponse time equalled the relative reciprocal of its length. In Exp. III, the relative frequency of an interresponse time was a monotonically increasing function of its relative frequency of reinforcement. These functions relating the relative frequency of an interresponse time to its relative length and to its relative frequency of reinforcement were the same as if there had been no second key. Also, the distribution of responses between keys was independent of the relative frequency of an interresponse time on either key. Experiment IV replicated Exp. I except that choices between keys were controlled by a stimulus that signalled the availability of reinforcement on the right key. A comparison of Exp. I and IV suggested that the relative frequency of an interresponse time on one key generally was independent of behavior on the other key, but that the number of responses per minute on a key did depend on behavior on the other key.
Journal of the experimental analysis of behavior, 1971 · doi:10.1901/jeab.1971.16-385